1. Field of the Invention
The present invention is broadly directed to cable and wire bundle clamps. More particularly, the present invention is directed to a cable or wire bundle clamp which requires no tools for fastening the clamp about the cable or wire bundle.
2. Brief Description of the Prior Art
Clamps for securing wire bundles, hoses, cables, and the like are well known to the prior art. Most of such clamps include an elongated strap which is designed to be disposed around the wire bundle or cable or other object to be gripped, and a fastener or strap receiving member to hold the strap in place once it is tightened around the wire bundle. The fastener or strap receiving member is usually permanently attached to one end of the strap, while the other end of the strap is either looped around the wire bundle and then inserted through an opening in the strap receiving member or the clamp is slipped over the object to be secured while both ends are held by the strap receiving member. The length of the strap extending around the wire bundle, etc., is then adjusted either manually by pulling on the free end of the strap or by means of a worm gear or screw which is designed to mate with appropriate teeth in the strap. In the former type of clamp the strap includes serrations which mate with a pawl member or the like secured to or formed integrally with the strap receiving member. Examples of the former type of clamps are found in U.S. Pat. Nos. 3,127,648; 3,900,922; 2,936,980; 3,537,146; 3,660,869; and examples of the latter type are found in U.S. Pat. Nos. 4,021,892; 3,914,832; 4,047,268; 3,924,308; 4,103,637; 4,099,304; 3,214,809 and 3,570,497. Additional disclosures generally relating to adjustable strap or band clamps are found in U.S. Pat. Nos. 3,214,809; 3,970,497; 2,995,328; 4,135,272; 3,967,345; 3,568,262; 3,875,618; 3,949,449; 3,542,321 and 3,672,615 and in British Patent Specification Nos. 1,013,500 and 1,006,129 and German Pat. No. 2,615,821.
As is well appreciated by those skilled in the art, cables, wire bundles or hose clamps used in such areas as aircraft should meet special strict requirements. For example, in an aircraft environment numerous cables and wire bundles must be secured to bulkheads, skin sections, etc., where there is very limited access. Thus the installer may find it not only difficult or impossible to use a tool to manipulate the clamp but may be unable to use more than one hand to fasten the clamp around the wire bundle, etc. The threading of the free end of the strap through the prior art fasteners with one hand is difficult, especially where access and/or visibility is limited. Wire bundles in aircraft are also often arranged in stacks or rows. While conventional prior art aircraft clamps of the C type allow the stacking of wire bundles in a stacked or Christmas tree fashion, all of the clamps above the one requiring attention must be removed before the mechanic or electronic technician can even get to the clamp which is holding the object to be removed. This involves a time-consuming and therfore expensive process. Such C type clamps also have the disadvantage of tending to pinch the wires which are adjacent the ends of the clamp secured by the bolt to the aircraft frame.
Clamps used in aircraft, as well as certain other environments, are also often subjected to extreme temperatures and severe vibration. Clamps fulfilling some of the needs in the prior art--especially for aircraft environments--are described in U.S. Pat. No. 4,303,216 and Applications Ser. Nos. 380,297 now U.S. Pat. No. 4,458,385 and 566,273 now U.S. Pat. No. 4,510,650 for "AVIONIC CLAMP HAVING SEPARATE STRAP AND LOCKING MEMBERS" and "CABLE CLAMP ASSEMBLY," which patent and applications are assigned to the same assignee as the present appication. The latter application was filed on Dec. 28, 1983 in the name of the same inventor as the present application.
The clamp described in U.S. Pat. No. 4,303,216 is of the worm or screw type and therefore a tool, such as a screwdriver or a wrench, is required to tighten the clamp. The clamp described in the above-mentioned Application Ser. No. 380,297 requires no such tool and is arranged to be manually tightened and readily disassembled. However, the clamp does require that the free end of the strap be inserted into and pushed through an opening in the strap receiving member after it has been looped around the wire bundle or cable before the free end protruding beyond the strap receiving member can then be grasped to tighten the strap. In areas where there is limited access it has been found that it is difficult for an operator to push the free end of the strap through the opening in the strap receiving member and past the serrated pawl after the strap has been looped around the wire bundle or cable. The clamp described in Application Ser. No. 566,273 permits a first end of the strap to remain free after the second end has been pushed through an opening in the strap receiving member and past the serrated pawl. The strap receiving member has an opening in the side thereof to receive the first end of the strap when inserted in a direction perpendicular to the side. This enables the first end of the strap to be looped around a wire bundle and then inserted into the strap receiving member. The second end of the strap may thus be pulled to lighten the strap. The serrated pawl includes a handle which may be pushed in a direction to disengage the serrations of the pawl and strap. It has been discovered, however, that the strap has a tendency to follow the movement of the pawl and prevent disengagement of the serrations, thereby making it difficult to disassemble the clamp.
The present invention is designed to fill the need in the prior art for a cable or wire bundle clamp which generally meets the requirements of an aircraft or similar hostile environment and which can be clamped around the cable or bundle of wires in an area with limited access and readily released when desired.